/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.hive.hplsql;

import java.math.BigDecimal;
import java.math.RoundingMode;
import java.sql.Date;
import java.sql.Timestamp;
import java.util.ArrayList;
import org.apache.hive.hplsql.executor.QueryResult;

/**
 * Variable or the result of expression 
 */
public class Var {
  // Data types
	public enum Type {BOOL, CURSOR, DATE, DECIMAL, DERIVED_TYPE, DERIVED_ROWTYPE, DOUBLE, FILE, IDENT, BIGINT, INTERVAL, ROW, 
	                  RS_LOCATOR, STRING, STRINGLIST, TIMESTAMP, NULL, HPL_OBJECT}
	public static final String DERIVED_TYPE = "DERIVED%TYPE";
	public static final String DERIVED_ROWTYPE = "DERIVED%ROWTYPE";
	public static Var Empty = new Var();
	public static Var Null = new Var(Type.NULL);
	
	public String name;
	public Type type; 
	public Object value;
	
	int len;
	int scale;
	
	boolean constant = false;

	public Var() {
	  type = Type.NULL;  
	}
	
	public Var(Var var) {
	  name = var.name;
    type = var.type;
    value = var.value;
    len = var.len;
    scale = var.scale;
  }
	
	public Var(Long value) {
    this.type = Type.BIGINT;
    this.value = value;
	}
	
	public Var(BigDecimal value) {
    this.type = Type.DECIMAL;
    this.value = value;
  }
  
	public Var(String name, Long value) {
    this.type = Type.BIGINT;
    this.name = name;    
    this.value = value;
  }
  
	public Var(String value) {
    this.type = Type.STRING;
    this.value = value;
  }
  
	public Var(Double value) {
    this.type = Type.DOUBLE;
    this.value = value;
  }
	
	public Var(Date value) {
    this.type = Type.DATE;
    this.value = value;
  }

	public Var(Timestamp value, int scale) {
    this.type = Type.TIMESTAMP;
    this.value = value;
    this.scale = scale;
  }
	
	public Var(Interval value) {
    this.type = Type.INTERVAL;
    this.value = value;
  }

	public Var(ArrayList<String> value) {
    this.type = Type.STRINGLIST;
    this.value = value;
  }
  
	public Var(Boolean b) {
    type = Type.BOOL;
    value = b;
  }
	
	public Var(String name, Row row) {
	  this.name = name;
	  this.type = Type.ROW;
	  this.value = new Row(row);
	}
	
	public Var(Type type, String name) {
    this.type = type;
    this.name = name;
  }
  
	public Var(Type type, Object value) {
    this.type = type;
    this.value = value;
  }
  
	public Var(String name, Type type, Object value) {
    this.name = name;
    this.type = type;
    this.value = value;
  }
	
	public Var(Type type) {
    this.type = type;
  }

  public Var(String name, String type, Integer len, Integer scale, Var def) {
	  this.name = name;
	  setType(type);
    if (len != null) {
      this.len = len;
    }
    if (scale != null) {
      this.scale = scale;
    }
    if (def != null) {
      cast(def);
    }
  }

	public Var(String name, String type, String len, String scale, Var def) {
	  this(name, type, len != null ? Integer.parseInt(len) : null, scale != null ? Integer.parseInt(scale) : null, def);
	}
	
	/**
	 * Cast a new value to the variable 
	 */
	public Var cast(Var val) {
	  try {
      if (constant) {
        return this;
      } else if (val == null || val.value == null) {
        value = null;
      } else if (type == Type.DERIVED_TYPE) {
        type = val.type;
        value = val.value;
      } else if (type == val.type && type == Type.STRING) {
        cast((String) val.value);
      } else if (type == val.type) {
        value = val.value;
      } else if (type == Type.STRING) {
        cast(val.toString());
      } else if (type == Type.BIGINT) {
        if (val.type == Type.STRING) {
          value = Long.parseLong((String) val.value);
        } else if (val.type == Type.DECIMAL) {
          value = ((BigDecimal)val.value).longValue();
        }
      } else if (type == Type.DECIMAL) {
        if (val.type == Type.STRING) {
          value = new BigDecimal((String) val.value);
        } else if (val.type == Type.BIGINT) {
          value = BigDecimal.valueOf(val.longValue());
        } else if (val.type == Type.DOUBLE) {
          value = BigDecimal.valueOf(val.doubleValue());
        }
      } else if (type == Type.DOUBLE) {
        if (val.type == Type.STRING) {
          value = Double.valueOf((String) val.value);
        } else if (val.type == Type.BIGINT || val.type == Type.DECIMAL) {
          value = Double.valueOf(val.doubleValue());
        }
      } else if (type == Type.DATE) {
        value = Utils.toDate(val.toString());
      } else if (type == Type.TIMESTAMP) {
        value = Utils.toTimestamp(val.toString());
      }
    } catch (NumberFormatException e) {
      throw new TypeException(null, type, val.type, val.value);
    }
	  return this;
	}

  /**
   * Cast a new string value to the variable 
   */
  public Var cast(String val) {
    if (!constant && type == Type.STRING) {
      if (len != 0 ) {
        int l = val.length();
        if (l > len) {
          value = val.substring(0, len);
          return this;
        }
      }
      value = val;
    }
    return this;
  }
	
	/**
	 * Set the new value 
	 */
	public void setValue(String str) {
	  if(!constant && type == Type.STRING) {
	    value = str;
	  }
	}
	
	public Var setValue(Long val) {
    if (!constant && type == Type.BIGINT) {
      value = val;
    }
    return this;
  }
	
	public Var setValue(Boolean val) {
    if (!constant && type == Type.BOOL) {
      value = val;
    }
    return this;
  }
	
	public void setValue(Object value) {
	  if (!constant) { 
      this.value = value;
	  }
  }

  public Var setValue(QueryResult queryResult, int idx) {
    int type = queryResult.jdbcType(idx);
    if (type == java.sql.Types.CHAR || type == java.sql.Types.VARCHAR) {
      cast(new Var(queryResult.column(idx, String.class)));
    } else if (type == java.sql.Types.INTEGER || type == java.sql.Types.BIGINT ||
            type == java.sql.Types.SMALLINT || type == java.sql.Types.TINYINT) {
      cast(new Var(Long.valueOf(queryResult.column(idx, Long.class))));
    } else if (type == java.sql.Types.DECIMAL || type == java.sql.Types.NUMERIC) {
      cast(new Var(queryResult.column(idx, BigDecimal.class)));
    } else if (type == java.sql.Types.FLOAT || type == java.sql.Types.DOUBLE) {
      cast(new Var(Double.valueOf(queryResult.column(idx, Double.class))));
    }
    return this;
  }

  public Var setRowValues(QueryResult queryResult) {
    Row row = (Row)this.value;
    int idx = 0;
    for (Column column : row.getColumns()) {
      Var var = new Var(column.getName(), column.getType(), (Integer) null, null, null);
      var.setValue(queryResult, idx);
      column.setValue(var);
      idx++;
    }
    return this;
  }

  /**
	 * Set the data type from string representation
	 */
	public void setType(String type) {
	  this.type = defineType(type);
	}
	
	/**
   * Set the data type from JDBC type code
   */
  void setType(int type) {
    this.type = defineType(type);
  }
  
  /**
   * Set the variable as constant
   */
  void setConstant(boolean constant) {
    this.constant = constant;
  }
	
	/**
   * Define the data type from string representation
   */
  public static Type defineType(String type) {
    if (type == null) {
      return Type.NULL;
    }
    else if (type.equalsIgnoreCase("INT") || type.equalsIgnoreCase("INTEGER") || type.equalsIgnoreCase("BIGINT") ||
             type.equalsIgnoreCase("SMALLINT") || type.equalsIgnoreCase("TINYINT") ||
             type.equalsIgnoreCase("BINARY_INTEGER") || type.equalsIgnoreCase("PLS_INTEGER") ||
             type.equalsIgnoreCase("SIMPLE_INTEGER") || type.equalsIgnoreCase("INT2") ||
             type.equalsIgnoreCase("INT4") || type.equalsIgnoreCase("INT8")) {
      return Type.BIGINT;
    }
    else if (type.equalsIgnoreCase("CHAR") || type.equalsIgnoreCase("VARCHAR") || type.equalsIgnoreCase("VARCHAR2") || 
             type.equalsIgnoreCase("STRING") || type.equalsIgnoreCase("XML") || type.equalsIgnoreCase("CHARACTER")) {
      return Type.STRING;
    }
    else if (type.equalsIgnoreCase("DEC") || type.equalsIgnoreCase("DECIMAL") || type.equalsIgnoreCase("NUMERIC") ||
             type.equalsIgnoreCase("NUMBER")) {
      return Type.DECIMAL;
    }
    else if (type.equalsIgnoreCase("REAL") || type.equalsIgnoreCase("FLOAT") || type.toUpperCase().startsWith("DOUBLE") ||
             type.equalsIgnoreCase("BINARY_FLOAT") || type.toUpperCase().startsWith("BINARY_DOUBLE") ||
             type.equalsIgnoreCase("SIMPLE_FLOAT") || type.toUpperCase().startsWith("SIMPLE_DOUBLE")) {
      return Type.DOUBLE;
    }
    else if (type.equalsIgnoreCase("DATE")) {
      return Type.DATE;
    }
    else if (type.equalsIgnoreCase("TIMESTAMP")) {
      return Type.TIMESTAMP;
    }
    else if (type.equalsIgnoreCase("BOOL") || type.equalsIgnoreCase("BOOLEAN")) {
      return Type.BOOL;
    }
    else if (type.equalsIgnoreCase("SYS_REFCURSOR")) {
      return Type.CURSOR;
    }
    else if (type.equalsIgnoreCase("UTL_FILE.FILE_TYPE")) {
      return Type.FILE;
    }
    else if (type.toUpperCase().startsWith("RESULT_SET_LOCATOR")) {
      return Type.RS_LOCATOR;
    }
    else if (type.equalsIgnoreCase(Var.DERIVED_TYPE)) {
      return Type.DERIVED_TYPE;
    }
    else if (type.equalsIgnoreCase(Type.HPL_OBJECT.name())) {
      return Type.HPL_OBJECT;
    }
    else if (type.equalsIgnoreCase(Type.ROW.name())) {
      return Type.ROW;
    }
    return Type.NULL;
  }
  
  /**
   * Define the data type from JDBC type code
   */
  public static Type defineType(int type) {
    if (type == java.sql.Types.CHAR || type == java.sql.Types.VARCHAR) {
      return Type.STRING;
    }
    else if (type == java.sql.Types.INTEGER || type == java.sql.Types.BIGINT) {
      return Type.BIGINT;
    }
    return Type.NULL;
  }
	
	/**
	 * Remove value
	 */
	public void removeValue() {
	  type = Type.NULL;  
    name = null;
    value = null;
    len = 0;
    scale = 0;
	}
	
	/**
	 * Compare values
	 */
	@Override
  public boolean equals(Object obj) {
	  if (getClass() != obj.getClass()) {
      return false;
    }    
	  Var var = (Var)obj;  
	  if (this == var) {
      return true;
	  }
	  else if (var == null || var.value == null || this.value == null) {
      return false;
    }
    if (type == Type.BIGINT) {
      if (var.type == Type.BIGINT && ((Long)value).longValue() == ((Long)var.value).longValue()) {
        return true;
      }
      else if (var.type == Type.DECIMAL) {
        return equals((BigDecimal)var.value, (Long)value);
      }
    }
    else if (type == Type.STRING && var.type == Type.STRING &&
            ((String)value).equals(var.value)) {
      return true;
    }
    else if (type == Type.DECIMAL && var.type == Type.DECIMAL &&
            ((BigDecimal)value).compareTo((BigDecimal)var.value) == 0) {
      return true;
    }
    else if (type == Type.DOUBLE) {
      if (var.type == Type.DOUBLE && ((Double)value).compareTo((Double)var.value) == 0) {
        return true;
      }
      else if (var.type == Type.DECIMAL && ((Double)value).compareTo(((BigDecimal)var.value).doubleValue()) == 0) {
        return true;
      }
    }
    return false;
	}
    
  /**
   * Check if variables of different data types are equal
   */
  public boolean equals(BigDecimal d, Long i) {
    if (d.compareTo(new BigDecimal(i)) == 0) {
      return true;
    }
    return false;
  }
	
	/**
   * Compare values
   */
  public int compareTo(Var v) {
    if (this == v) {
      return 0;
    }
    else if (v == null) {
      return -1;
    }
    else if (type == Type.BIGINT && v.type == Type.BIGINT) {
      return ((Long)value).compareTo((Long)v.value);
    }
    else if (type == Type.DOUBLE && v.type == Type.DECIMAL) {
      return (new BigDecimal((double)value)).compareTo((BigDecimal)v.value);
    }
    else if (type == Type.STRING && v.type == Type.STRING) {
      return ((String)value).compareTo((String)v.value);
    }
    return -1;
  }
  
  /**
   * Calculate difference between values in percent
   */
  public BigDecimal percentDiff(Var var) {
    BigDecimal d1 = new Var(Var.Type.DECIMAL).cast(this).decimalValue();
    BigDecimal d2 = new Var(Var.Type.DECIMAL).cast(var).decimalValue();
    if (d1 != null && d2 != null) {
      if (d1.compareTo(BigDecimal.ZERO) != 0) {
        return d1.subtract(d2).abs().multiply(new BigDecimal(100)).divide(d1, 2, RoundingMode.HALF_UP);
      }
    }
    return null;
  }
	
	 /**
   * Increment an integer value
   */
  public Var increment(long i) {
    if (type == Type.BIGINT) {
      value = Long.valueOf(((Long) value).longValue() + i);
    }
    return this;
  }

  /**
  * Decrement an integer value
  */
  public Var decrement(long i) {
    if (type == Type.BIGINT) {
      value = Long.valueOf(((Long) value).longValue() - i);
    }
    return this;
  }
  
	/**
	 * Return an integer value
	 */
	public int intValue() {
	  if (type == Type.BIGINT) {
	    return ((Long)value).intValue();
	  }
	  else if (type == Type.STRING) {
	    return Integer.parseInt((String)value);
	  }
	  throw new NumberFormatException();
	}
	
	/**
   * Return a long integer value
   */
  public long longValue() {
    if (type == Type.BIGINT) {
      return ((Long)value).longValue();
    }
    throw new NumberFormatException();
  }
  
  /**
   * Return a decimal value
   */
  public BigDecimal decimalValue() {
    if (type == Type.DECIMAL) {
      return (BigDecimal)value;
    }
    throw new NumberFormatException();
  }
  
  /**
   * Return a double value
   */
  public double doubleValue() {
    if (type == Type.DOUBLE) {
      return ((Double)value).doubleValue();
    }
    else if (type == Type.BIGINT) {
      return ((Long)value).doubleValue();
    }
    else if (type == Type.DECIMAL) {
      return ((BigDecimal)value).doubleValue();
    }
    throw new NumberFormatException();
  }
	
	/**
	 * Return true/false for BOOL type
	 */
	public boolean isTrue() {
	  if(type == Type.BOOL && value != null) {
	    return ((Boolean)value).booleanValue();
	  }
	  return false;
	}
	
	/**
	 * Negate the value
	 */
	public void negate() {
    if (value == null){
      return;
    }
    if (type == Type.BOOL) {
      boolean v = ((Boolean)value).booleanValue();
      value = Boolean.valueOf(!v);
    }
    else if (type == Type.DECIMAL) {
      BigDecimal v = (BigDecimal)value;
      value = v.negate();
    }
    else if (type == Type.DOUBLE) {
      Double v = (Double)value;
      value = -v;
    }
    else if (type == Type.BIGINT) {
      Long v = (Long)value;
      value = -v;
    }
    else {
      throw new NumberFormatException("invalid type " + type);
    }
  }
	
	/**
	 * Check if the variable contains NULL
	 */
	public boolean isNull() {
    if (type == Type.NULL || value == null) {
      return true;
    }
    return false;
  }
	
	/**
	 * Convert value to String
	 */
	@Override
  public String toString() {
	  if (type == Type.IDENT) {
      return name;
    }   
	  else if (value == null) {
	    return null;
	  }
	  else if (type == Type.BIGINT) {
	    return ((Long)value).toString();
	  }
	  else if (type == Type.STRING) {
      return (String)value;
    }
    else if (type == Type.DATE) {
      return ((Date)value).toString();
    }
    else if (type == Type.TIMESTAMP) {
      int len = 19;
      String t = ((Timestamp)value).toString();   // .0 returned if the fractional part not set
      if (scale > 0) {
        len += scale + 1;
      }
      if (t.length() > len) {
        t = t.substring(0, len);
      }
      return t;
    }
	  return value.toString();
	}

  /**
   * Convert value to SQL string - string literals are quoted and escaped, ab'c -&gt; 'ab''c'
   */
  public String toSqlString() {
    if (value == null) {
      return "NULL";
    }
    else if (type == Type.STRING) {
      return Utils.quoteString((String)value);
    }
    return toString();
  }
	
  /**
   * Set variable name
   */
  public void setName(String name) {
    this.name = name;
  }
  
	/**
	 * Get variable name
	 */
	public String getName() {
	  return name;
	}
}
